Mechanisms of T-cell induced-APC cytotoxicity in lupus

描述(由申请人提供)：申请申请的具体目的是由首席研究员开发一个独立的研究项目。申请人在过去四年一直在从事T细胞免疫学和狼疮发病机制方面的基础科学研究。该提案是申请人目前对单核/巨噬细胞(M Theta)凋亡研究的扩展。假设：凋亡诱导分子介导由CD4+狼疮T细胞引起的自体单核细胞/M theta杀伤。通过这种机制杀死靶细胞可以导致自身抗体的产生。目的：探讨狼疮CD4+T细胞诱导单核细胞/M theta细胞凋亡的途径。申请者将测试是否有可能通过阻断自身反应性CD4+T细胞参与单核细胞/M theta杀伤的凋亡途径来抑制SLE动物模型中自身免疫的发展。巨噬细胞凋亡在触发或增强自身免疫中的作用也将被研究。方法：1)用流式细胞术检测SLE和对照T细胞表面死亡受体配体的表达。B)通过细胞毒试验，确定这些凋亡通路在SLE单核细胞/M theta中是否起作用，以及阻断这些分子是否可以抑制SLE T细胞对自体单核细胞/M theta的杀伤作用。C)考虑到参与M theta细胞毒性的通路的冗余性，申请人将在体外测试，抑制死亡受体(FADD、caspase、flip)下游的死亡信号是否足以抑制这些配体诱导的单核细胞/M theta凋亡。D)体内研究将试图确定单抗或融合蛋白对单核/巨噬细胞死亡受体配体的阻断是否可以抑制小鼠系统性红斑狼疮的发展，以及组织巨噬细胞本身的消除是否足以在动物模型中诱导自身免疫。提出的研究结果可能确定SLE自身抗原产生的潜在机制。这些可能导致开发旨在逆转这些异常的治疗干预措施，并取消或阻止这种疾病的发生和严重程度。赞助商和机构承诺为申请者提供受保护的时间、职业发展和资源。

DESCRIPTION (provided by applicant): The application requests funding with the specific intent of developing an independent research program by the principal investigator. The applicant has been pursuing basic science research in the areas of T cell immunology and pathogenesis of lupus (SLE) for the past four years. The proposal is an extension of the applicant's current research on monocyte/macrophage (M theta) apoptosis. Hypothesis: Apoptosis-inducing molecules mediate the autologous monocyte/M theta killing caused by CD4+ lupus T cells. Target cell killing by this mechanism can lead to the generation of autoantibodies. Specific aims: To determine the pathways involved in monocyte/M theta apoptosis induced by lupusCD4+ T cells. The applicant will test whether it's possible to inhibit the development of autoimmunity in an SLE animal model, by blocking the apoptotic pathways involved in monocyte/M theta killing by autoreactive CD4+ T cells. The role of macrophage apoptosis in triggering or augmenting autoimmunity will also be investigated. Methods: a) Measurement of cell surface expression of death-receptor ligands on SLE and control T cells by flow cytometry. b) With cytotoxicity assays, determine whether these apoptotic pathways are functional in SLE monocytes/M theta and whether blocking these molecules can inhibit the autologous monocyte/M theta killing by SLE T cells. c) Given the redundancy of the pathways involved in M theta cytotoxicity, the applicant will test, in vitro, if inhibiting the death signals downstream of the death receptors (FADD, caspases, FLIP) is sufficient to inhibit monocyte/M theta apoptosis induced by these ligands. d) In vivo studies will try to characterize whether the blockade on monocyte/macrophage death-receptor ligands by monoclonal antibodies or fusion proteins, can inhibit the development of murine SLE, and whether the elimination of tissue macrophages; per se (with clodronate liposomes in vivo) is sufficient to induce autoimmunity in an animal model. The results of the studies proposed might identify potential mechanisms involved in the generation of autoantigens in SLE. These could lead into the development of therapeutic interventions designed to reverse these abnormalities and abrogate or block the onset and severity of this disease. The sponsor and the institution are committed to contributing protected time, career development and resources to the applicant.